1. Field
This disclosure is concerned generally with blood bags useful for the collection, processing and storage of blood and blood components. The disclosure is specifically concerned with a blood bag system useful for the preparation and long term storage of neocytes and gerocytes.
2. Prior Art
Plastic blood bag systems for the collection, processing and storage of blood and blood components are well known and have been used for thirty or more years. In early embodiments, when plastic films were used to make bags that ultimately replaced glass bottles, many of the plastic blood bag systems were "open" in the sense that there existed the chance of contamination as blood or separated blood components were moved into or out of the system. Quite often, the plastic bag system was a single bag having attached to it one or more tubings and ports for adding or removing bag contents. See, for example, U.S. Pat. No. 2,702,034 to Walter, U.S. Pat. No. 3,327,709 to Nehring et al., and U.S. Pat No. 3,416,528 to Kahn.
As the use of various components and sub-components of blood became accepted, attempts were made to avoid potential contamination problems by providing multiple blood bags attached to each other by tubings and including valving systems. See, for example, U.S. Pat. No. 3,058,799 to Rowles et al. and U.S. Pat. No. 4,332,122 to Williams. Such systems became known as doubles, triples, quads, etc., depending on the number of blood bags in the system. These multiple blood bag systems are known as "closed" in the sense that there no longer exists the chance of contamination after whole blood or a major component (e.g. plasma or a red cell concentrate) is introduced into and processed in the system.
Depending on design, the number of bags and such factors as valving systems and internal solutions, there now exists a variety of closed multiple blood bag systems. Available systems permit the collection, processing and storage of well known blood components such as red cell concentrates, plasma, and platelets.
In a typical application, whole blood is collected from a donor via a phlebotomy needle and passed through a plastic tubing into a first bag commonly known as the donor bag. The donor bag usually includes an anticoagulant solution to keep the whole blood from clotting. Connected to the donor bag via tubings and valves are one or more satellite bags in closed communication with the donor bag.
In one example, a triple multiple blood bag system consisting of a donor bag and two empty satellite bags is used to collect blood from a donor (into the donor bag). The entire triple system is then put in a centrifuge cup and centrifuged to form in the donor bag an upper lighter plasma portion and a lower heavier red blood cell (RBC) concentrate portion. After opening a valve in the system, the upper plasma portion is expressed into one of the satellite bags. This leaves the red cell concentrate behind in the donor bag which may be detached. The red cell concentrate is then commonly stored for up to 35 days before transfusion to a patient needing that type of RBCs.
The plasma-containing satellite bag may then be centrifuged to separate the plasma into an upper portion of platelet poor plasma and a lower heavier portion of platelet-concentrate. The upper platelet poor plasma may be expressed in to an empty satellite bag for subsequent pooling with other platelet poor plasma. Such plasma pools may then be fractionated into components such as albumin, coagulation factors, antibodies and the like. The remaining platelet concentrate may then be administered to a platelet deficient patient alone, or more commonly, after pooling with several other platelet concentrates.
Although blood bags have been available as singles, doubles, triples and quads, their use as closed systems has generally been limited to the basic type of separations and storage as described above for triples.
Recently, however, variations on the above basic system have been devised. For example, with the advent of so-called sterile docking systems (see U.S. Pat. No. 4,507,119 and U.S. Pat. No. 4,443,215), one can collect, process and store various blood components and still maintain a closed system with or without using the classic multiple blood bag systems. Sterile docking systems permit the communication of two originally disconnected bags but under conditions that do not jeopardize sterility during the communication process. Thus, sterile docked systems can be referred to as closed systems even though not originally connected as classic multiple blood bag systems.
Along with the above variations, including sterile docking, recent attention has been given to the use of blood bag designs for blood component enhancement. For example, an integral white blood cell (WBC) filter can be made part of a closed system for the preservation of red blood cells (RBC's). See U.S. Pat. No. 4,767,541 to L. Wisdom and U.S. Pat. No. 4,810,378 to R. Carmen et al. Further, as shown in EP Application No. 0,191,360 the geometry of blood bags may be specially modified to accomplish a finer separation of certain components such as neocytes and gerocytes. In addition, at least two closed systems have been described for the preparation of neocytes and gerocytes from a conventional red blood cell concentrate. In U.S. Pat. No. 4,416,778 to Rogers, a specially modified system of connected blood containers is shown for preparation of neocytes. In EPO Application No. 0,191,360, a double bag system is disclosed showing a specially designed bag (elongated and having a funnel shaped exit) for the separation of neocytes and their subsequent expression into a connected bag.
It is against the above background that the invention of the present disclosure arose. We have created a novel closed blood bag system which permits the filtration of RBC's and their subsequent processing into useable neocytes that, because of our system, can be stored for up to 42 days. Details of our system and methods of using it and its preferred variations are described below.